Responsivity

About: Responsivity is a research topic. Over the lifetime, 9918 publications have been published within this topic receiving 186118 citations.

Waveguide-integrated van der Waals heterostructure photodetector at telecom wavelengths with high speed and high responsivity.

Abstract: Intensive efforts have been devoted to the exploration of new optoelectronic devices based on two-dimensional transition-metal dichalcogenides (TMDCs) owing to their strong light–matter interaction and distinctive material properties. In particular, photodetectors featuring both high-speed and high-responsivity performance are of great interest for a vast number of applications such as high-data-rate interconnects operated at standardized telecom wavelengths. Yet, the intrinsically small carrier mobilities of TMDCs become a bottleneck for high-speed application use. Here, we present high-performance vertical van der Waals heterostructure-based photodetectors integrated on a silicon photonics platform. Our vertical MoTe2–graphene heterostructure design minimizes the carrier transit path length in TMDCs and enables a record-high measured bandwidth of at least 24 GHz under a moderate bias voltage of –3 V. Applying a higher bias or employing thinner MoTe2 flakes boosts the bandwidth even to 50 GHz. Simultaneously, our device reaches a high external responsivity of 0.2 A W–1 for incident light at 1,300 nm, benefiting from the integrated waveguide design. Our studies shed light on performance trade-offs and present design guidelines for fast and efficient devices. The combination of two-diemensional heterostructures and integrated guided-wave nano photonics defines an attractive platform to realize high-performance optoelectronic devices, such as photodetectors, light-emitting devices and electro-optic modulators. The low carrier mobilities of TMDCs pose a challenge for applications in high-speed photodetection. Integrating vertical two-dimensional heterostructures with photonic waveguides allows the intrinsic speed limitations to be overcome and record-high photodetection bandwidths to be achieved.

Single-crystalline In2S3 nanowire-based flexible visible-light photodetectors with an ultra-high photoresponse.

Abstract: With a band gap of 2.28 eV, In2S3 is an excellent candidate for visible-light sensitive photodetectors. By growing single-crystalline In2S3 nanowires via a simple CVD method, we report the fabrication of high-performance single-crystal In2S3 nanowire-based flexible photodetectors. The as-fabricated flexible photodetectors exhibited an ultra-high Ion/Ioff ratio up to 106 and a high sensitivity to visible incident light with responsivity and quantum efficiency as high as 7.35 × 104 A W−1 and 2.28 × 107%, respectively. Besides, the flexible photodetectors were demonstrated to possess a robust flexibility and excellent stability. With these favorable merits, In2S3 nanowires are believed to have a promising future in the application of high performance and flexible integrated optoelectronic devices.

Solution-Processed, High-Speed, and High-Quantum-Efficiency Quantum Dot Infrared Photodetectors

Abstract: For over a decade, much effort has been focused on passivation of the high density of localized electronic trap states in colloidal semiconductor quantum dots (QDs), which lead to reduced performance in solar cell, light-emitting diode, laser, and photoconductor applications. However, here we take advantage of the naturally occurring high density of trap states to demonstrate solution-processed high-speed PbSe quantum dot near-infrared photodetectors. Carrier transport dynamics studies reveal multiple trapping and release transport dynamics in band tail states. A sandwich microstrip transmission line photodetector utilizing these QD films was fabricated to achieve high performance by allowing carriers to be swept to the electrodes before they fall into the band tail states. This device demonstrates external quantum efficiency, responsivity, and response time (full width at half-maximum) of 54%, 0.36 A/W, and 74 ps, respectively.

A high responsivity, broadband waveguide uni-travelling carrier photodiode

Abstract: A 02 A/W responsivity waveguide-uni-travelling carrier photodiode with a -3 dB electrical frequency response > 108 GHz is demonstrated Up to -5 dBm electrical power at 110 GHz, and 28 mA photocurrent (DC excitation) were detected The photodiode was also integrated with an antenna to permit a record breaking emission of up to 148 μW at 457 GHz and 25 μW at 914 GHz

Enhancing photoresponsivity using MoTe2-graphene vertical heterostructures

Abstract: MoTe2 with a narrow band-gap of ∼1.1 eV is a promising candidate for optoelectronic applications, especially for the near-infrared photo detection. However, the photo responsivity of few layers MoTe2 is very small (<1 mA W−1). In this work, we show that a few layer MoTe2-graphene vertical heterostructures have a much larger photo responsivity of ∼20 mA W−1. The trans-conductance measurements with back gate voltage show on-off ratio of the vertical transistor to be ∼(0.5–1) × 105. The rectification nature of the source-drain current with the back gate voltage reveals the presence of a stronger Schottky barrier at the MoTe2-metal contact as compared to the MoTe2-graphene interface. In order to quantify the barrier height, it is essential to measure the work function of a few layers MoTe2, not known so far. We demonstrate a method to determine the work function by measuring the photo-response of the vertical transistor as a function of the Schottky barrier height at the MoTe2-graphene interface tuned by elec...